From 94aaadacf7daa6edf94724b1dee9549a60cc6498 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= <egil@erlang.org>
Date: Thu, 7 May 2015 17:23:23 +0200
Subject: doc: Update efficiency guide with Maps memory info

---
 system/doc/efficiency_guide/advanced.xml | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'system')

diff --git a/system/doc/efficiency_guide/advanced.xml b/system/doc/efficiency_guide/advanced.xml
index 3609b8d88e..26e0c57e81 100644
--- a/system/doc/efficiency_guide/advanced.xml
+++ b/system/doc/efficiency_guide/advanced.xml
@@ -86,6 +86,19 @@
         <cell>Tuple</cell>
         <cell>2 words + the size of each element.</cell>
       </row>
+      <row>
+        <cell>Small Map</cell>
+        <cell>4 words + 2 words per entry (key and value) + the size of each key and value pair.</cell>
+      </row>
+      <row>
+        <cell>Large Map</cell>
+        <cell>
+            At least, 2 words + 2 x <c>N</c> words + 2 x log16(<c>N</c>) words +
+            the size of each key and value pair, where <c>N</c> is the number of pairs in the Map.
+            A large Map is represented as a tree internally where each node in the tree is a
+            "sparse tuple" of arity 16.
+        </cell>
+      </row>
       <row>
         <cell>Pid</cell>
         <cell>1 word for a process identifier from the current local node
-- 
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